Looks like a telephone pole insulator.
Don...
Looks like it some sort of ashtray, made by a company called Houze X Glass Co of Point Marion, PA...here's a few examples, one that shows the same type of bracket.
HouzeX Car Ashtray (nia.org)
They seem to sell well:
houze ashtray | eBay

Treasurekidd, That's what I was told 20 years ago, an old timer told me it went to a Model T Ford but I never could find info on it, you are the first to lead me to a page about them, a very big thank you, I also dug a lens that looked like it went to a rear lite to a car, with this, it was red and a half inch thick, if I can find it I will post a pic, it's funny, over the years there is more and more info on the net about stuff